Highly dispersed TiO2 nanocrystals and carbon dots on reduced graphene oxide: Ternary nanocomposites for accelerated photocatalytic water disinfection
Highly dispersed TiO2 nanocrystals and carbon dots on reduced graphene oxide: Ternary nanocomposites for accelerated photocatalytic water disinfection
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DOI：
10.1016/j.apcatb.2016.09.014
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发表时间：
2017-03
影响因子：
22.1
通讯作者：
Xiangkang Zeng;Zhouyou Wang;Na Meng;D. Mccarthy;A. Deletic;J. Pan;Xiwang Zhang
中科院分区：
文献类型：
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作者：
Xiangkang Zeng;Zhouyou Wang;Na Meng;D. Mccarthy;A. Deletic;J. Pan;Xiwang Zhang
石墨烯被广泛用作催化剂载体，用于改善TiO 2纳米粒子中的电荷分离。然而，石墨烯的电子储存能力可能会阻碍TiO 2/石墨烯的表面氧还原活性。以TiCl 4和葡萄糖为原料，通过简单的水热反应合成了高度分散的TiO 2和碳点（C-dots）共修饰的还原氧化石墨烯（CTR）。采用透射电子显微镜、X射线衍射、拉曼光谱、热重分析和傅里叶变换红外光谱对CTR纳米复合材料进行了表征。对比实验证实了碳点来源于葡萄糖的碳化。葡萄糖和TiCl 4是相互分散剂，对形成高度分散且尺寸均匀的C点和TiO 2纳米晶至关重要。在还原的氧化石墨烯表面的分离位点上具有良好分散的TiO 2和C点，CTR在模拟太阳光下显示出增强的光催化细菌灭活性能。通过活性氧的生成确认，超氧阴离子（O2 radical dot-）和过氧化氢（H2 O2）的生成得到改善。电化学表征表明，CTR膜的电荷分离也得到了促进。总之，同时改善的电荷分离和表面氧还原活性有助于加速光催化细菌灭活过程。
Graphene is widely used as a catalyst support for improved charge separation in TiO2photocatalysis. However, the surface oxygen reduction activity of TiO2/graphene might be hindered due to the electron storage ability of graphene. In this study, highly dispersed TiO2and carbon dots (C-dots) co-decorated reduced graphene oxide (CTR) is synthesized via a simple hydrothermal reaction using TiCl4and glucose. Transmission electron microscope, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis and Fourier transform IR spectroscopy are employed to characterize the CTR nanocomposite. The comparison experiment confirmed that C-dots were sourced from the carbonization of glucose. Glucose and TiCl4which are mutual dispersants, are critical for forming highly dispersed and uniform-sized C-dots and TiO2nanocrystals. With well dispersed TiO2and C-dots at separated sites of reduced graphene oxide surface, CTR shows enhanced photocatalytic bacterial inactivation performance under simulated solar light. As confirmed by the reactive oxygen species production, the generation of superoxide anion (O2radical dot−) and hydrogen peroxide (H2O2) is improved. The electrochemical characterization reveals that charge separation in CTR photocatalysis is also promoted. Taken together, the concurrently improved charge separation and surface oxygen reduction activity contribute to an accelerated photocatalytic bacteria inactivation process.